.\"	$NetBSD: npf.7,v 1.3 2015/07/12 23:54:43 rmind Exp $
.\"
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.\" This material is based upon work partially supported by The
.\" NetBSD Foundation under a contract with Mindaugas Rasiukevicius.
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.Dd July 13, 2015
.Dt NPF 7
.Os
.Sh NAME
.Nm NPF
.Nd NetBSD packet filter
.\" -----
.Sh DESCRIPTION
NPF is a layer 3 packet filter, supporting IPv4 and IPv6 as well as
layer 4 protocols such as TCP, UDP, and ICMP.
It was designed with a focus on high performance, scalability, and
modularity.
.Pp
NPF was written from scratch in 2009 and is distributed under the
2-clause BSD license.
.\" -----
.Sh FEATURES
NPF offers the traditional set of features provided by packet filters.
Some key features are:
.Bl -bullet -offset indent
.It
Stateful inspection (connection tracking).
.It
Network address translation (NAT).
This includes static (stateless) and dynamic (stateful) translation,
port translation, bi-directional NAT, etc.
.It
IPv6-to-IPv6 network prefix translation (NPTv6).
.It
Tables for efficient IP sets.
.It
Application Level Gateways (e.g., to support traceroute).
.It
NPF uses BPF with just-in-time (JIT) compilation.
.It
Rule procedures and a framework for NPF extensions.
.It
Traffic normalization (extension).
.It
Packet logging (extension).
.El
.Pp
For a full set of features and their description, see the NPF
documentation and other manual pages.
.\" -----
.Sh SEE ALSO
.Xr libnpf 3 ,
.Xr bpf 4 ,
.Xr bpfjit 4 ,
.Xr npf.conf 5 ,
.Xr pcap-filter 7 ,
.Xr npfctl 8
.Pp
.Lk http://www.netbsd.org/~rmind/npf/ "NPF documentation"
.Sh HISTORY
.Nm
first appeared in
.Nx 6.0 .
.Sh AUTHORS
.Nm
was designed and implemented by
.An Mindaugas Rasiukevicius .